Chinese security forces killed 28 "terrorists," state media say, during a weeks-long search for those who carried out a deadly attack at a coal mine in the country's ethnically divided Xinjiang region.

The reports published Friday were the first official confirmation of the gruesome September 18 attack on the coal mine in Aksu prefecture, which officials said killed 16 people, including 5 policemen.

Following the attack, the assailants fled into the nearby mountains, prompting a massive manhunt that lasted 56 days and involved the assistance of around 10,000 people, according to local officials.

Security forces eventually "busted" the alleged terrorist gang, according to the Xinhua news agency, killing 28 of its members. One other member was arrested, it added.

The group was operating "under the direct command of an overseas extremist organization" and was headed by two people with apparently Uighur-sounding names, according to the Xinjiang regional government.

China says it is fighting a foreign-backed separatist movement in Xinjiang, where the mostly Muslim, Turkic-speaking Uighurs have long complained of cultural and religious persecution.

The region has seen a wave of deadly unrest in recent years. Many of the attacks initially focused on government or security targets, but have increasingly targeted innocent civilians.

Beijing has kept a tight lid on information about the Xinjiang violence, including the September coal mine attack, which was reported on by foreign media, but not discussed in state-run papers.

Radio Free Asia, which is funded by the U.S. government, reported that at least 50 people had died in the incident.

Exiled Uighur right groups, which regularly question China's claims on violence in Xinjiang, have not responded to Beijing's latest statements.